Sending Email with SendGrid

You can use SendGrid to power your emails on Google App Engine. Using SendGrid
can improve your deliverability and provide transparency into what actually
happens to those emails your app sends. You can see statistics on opens,
clicks, unsubscribes, spam reports and more through either the SendGrid
interface or its API.

Pricing

Google App Engine customers can send 12,000 emails every month for free. Follow
the steps below to sign up for the free emails and to see higher volume plans.

Before you begin

To begin, you'll need to:

Create or select a GCP project in the GCP Console
and then ensure that project includes an App Engine application:

Getting real-time information

In addition to sending email, SendGrid can help you receive email or make sense
of the email you’ve already sent. The two real-time webhook solutions can
greatly enhance the role email plays in your application.

Using the Event API

Once you start sending email from your app, you'll want to know more about how
it's performing. The statistics within SendGrid are one of its best features.
The Event API lets
you see all this data as one giant firehose. Whenever a recipient opens or
clicks an email, for example, SendGrid can send a small bit of descriptive JSON
to your Google App Engine app. You can react to the event or store the data for
future use.

There are many different applications of event data. Some common uses are to
integrate email stats into internal dashboards or use it to respond immediately
to unsubscribes and spam reports. Advanced users of the Event API raise the
engagement of their emails by sending only to those who have clicked or opened
within the last few months.

The Event API documentation shows
how to set up the webhook, outlines the nine event types and shows the fields
included in event callbacks.

Using the Inbound Parse API

You can also use SendGrid to receive email. The
Inbound Parse API can be used for
powerful, interactive applications. For example, automate support tickets from
customer emails, or collect data via short emails employees dispatch from the
road. NudgeMail's reminder
application is even built entirely
on the Parse API.

Like the Event API, the Parse API is a webhook that sends data to your
application when something new is available. In this case, the webhook is called
whenever a new email arrives at the domain you've associated with incoming
email. Due to intricacies in the way DNS works for email, you need to assign all
incoming mail to the domain or subdomain you use for the Parse API.

Emails are sent to your application structured as JSON, with sender, recipients,
subject and body as different fields. You can even accept attachments, within
SendGrid’s limit of messages up to 20 MB in size.

The Parse API documentation has
more details, including additional fields sent with every email, as well as
instructions for DNS setup and usage.

* Google will be compensated for customers who sign up for a non-free account.